Steve Warson is an American race car pilot, being a mainstay character since album #1 [1]. He was first introduced as an opponent to Michel Vaillant before becoming a close friend to him, although he can be a loner as well while following his own agenda. This sometimes even means working for Vaillante's arch-nemesis, Leader.

Michel first meets Steve when Vaillante decides to challenge the reigning American autosports champions. When Team Vaillante lands in the United States of America, Warson is there, waiting for them. While Michel tries to shake hands, Warson just stands there, only remarking to an aide standing by to "Get me a sigaret" and "get me a light". After that, he turns around and drives off, leaving a very confused Team Vaillante behind. However, his confidence in his superiority gets shaken up pretty badly. While he wins the first race in Argentina, he gets beaten at the match in Indianapolis. He leaves the track dissatisfied, vowing to defeat Vaillante during the next match, which will take place on the circuit of Francorchamps.

His relationship with the Vaillants improves dramatically over the course of the album though, up until the point that Michel can sincerely call him a friend. After Steve crashes during the last race on the Nurnbergring, Michel gives up his price to Steve, commenting that it's only fair Steve would be the winner, not him. After visiting him in the hospital, Team Vaillante decides to take him in as a pilot. He recovers just in time to attend the wedding of Jean-Pierre and Agnes de Chanzy.